YES!! Ugh! This is the bane of my name-loving existence. Usually, for me, it happens when I like a character from TV/film and the actors all have accents. I loved Eirene from Rome, and all the characters pronounced it ay-REH-nee, which may or may not be the correct pronunciation, but regardless it would be pronounced like Eireen/Irene on first glance where I live. I thought it was Noreni for the longest time.

Same thing happened with Ianthe (heard eye-ANN-thee, it's actually ee-ANN-thee or ee-ANN-tee, even YANN-thee) and Niobe (heard neye-OH-bee, it's actually NEE-oh-bee, but apparently this is up for debate... but someone on NB pointed out that it sounds like Nairobi :P). Those Latin and Greek names are tricky buggers.